<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        div{
            width: 500px;
            height: 500px;
            background-color: aquamarine;
            /* 边框线 == 纸箱子 */
            border: 1px solid #000;
            /* 内边距 == 填充泡沫  */
            padding: 20px;
            /*  外边距 ：出现在两个盒子之间，之外 */
            margin: 60px;
        }

    </style>
</head>

<body>
    <div>
        computer
    </div>
    <div>
        notepad
    </div>
</body>
</html>
